How to transition from brownfield SCADA to greenfield IoT

Companies looking to modernize their control and analytics systems have options

· 3AG blog

In recent posts, we’ve talked much about supervisory control and data acquisition (SCADA) systems, which are used to control and measure the performance of equipment in many kinds of industrial operations. We have also considered some of the limitations of traditional SCADA systems, and how they differ from modern internet of things (IoT) installations. However, we have not looked at some practical considerations for companies looking to either upgrade or replace existing SCADA systems with 21st century technology. Is it worth the cost and effort to upgrade an existing (brownfield) operation? Or, in terms of your return on investment, should you instead make the wholesale change to a new (greenfield) solution?

old farm equipment

The high cost of maintaining legacy systems

When doing a cost benefit analysis for a new system, you are going to be faced with the cost of the new system vs. the alternative of doing nothing, i.e., the status quo. While it can be tempting to see the status quo as the cheapest option, this is not always the case.

In When Legacy Becomes Loss: The True Costs of Legacy Systems, Tracey Ruff identifies nine true costs of holding on to legacy systems, including:

  • Hidden costs due to performance and speed
  • Lack of mobile access
  • Poor employee/user experience
  • Lack of scalability
  • Security threats
  • High cost of ownership
  • Support and maintenance costs

The last two points underline the not-so-hidden cost of doing nothing. In a 2019 study from the US Government Accountability Office, 80% of the $90 billion IT budget for 2019 was earmarked for operating and maintaining existing IT investments, including legacy systems. These old systems become more expensive over time as their effective functionality ages. For example, “the selected legacy system at the Department of Education runs on Common Business Oriented Language (COBOL)—a programming language that has a dwindling number of people available with the skills needed to support it.” COBOL, by the way, was standardized as a programming language in 1968. SCADA came on the scene in the mid-1970s.

Legacy systems don’t become expensive to maintain overnight; rather, their cost increases through a gradual accumulation of technical debt over a period of years and decades. Make sure you do a full cost analysis before settling for the status quo.

people gathered in state assembly

How to build an incremental change path

For an organization with an existing SCADA system, the decision either to keep the existing system or rip it out and replace it with an IoT solution can be difficult to make. Thankfully, the decision doesn’t have to be binary, as there are multiple paths to an upgraded system, including:

  • Incremental addition of IoT sensors
  • Shadow IoT solution
  • Streaming of existing SCADA system to IoT hub
  • Wholesale change to IoT system

Let’s consider these options.